Magnetic separator



Jan; 13, 1970 A. G. ST. PIER'RE MAGNETIC SEPARATOR 2 Sheets-Sheet 1 Filed Feb. 20, 1968 r R. W 6, mfi "1 6. Q W J m Z, m m \GQ Jan. 13, 1970 A. G. ST. PIERRE 3,489,281

MAGNET I C SEPARATOR Filed Feb. 20, 1968 7 2 Sheets-Sheet 2 United States Patent O 3,489,281 MAGNETIC SEPARATOR Albert G. St. Pierre, Unionville, Conn., assrgnor to Michael A. Suisman, West Hartford, Conn. Filed Feb. 20, 1968, Ser. No. 706,827

Int. c1. B03c 1/14 US. (:1. 209-223 5 CIalmS ABSTRACT OF THE DISCLOSURE A vibrating tray feeds a mixture of magnetic and nonmagnetic material onto a non-rotating magnetrzedsegment of a rotating drum. The drum is not magnetic so that non-magnetic material drops from the drum and magnetic material is carried through the magnetized segment. Another drum, mounted slightly higher than the first on an inclined frame, also has a non-rotating magnetized segment, and the polarity of the segments are such that the magnetic material is transferred onto the magnet c segment of the second drum with additional non-magnetic material being dropped off in the process. An inclined surface below these, and other similar drums on the inclined frame, carries the non-magnetic material in one direction beneath the drums while the magnetic material travels along the magnetic drum segments generally in the opposite direction.

SUMMARY OF INVENTION This invention relates to magnetic separators, and deals more particularly with an apparatus which is capable of segregating a very high percentage of purely magnetic material from a heterogeneous mixture of magnetic and non-magnetic material.

A primary object of the present invention is to provide a magnetic separator in which only magnetic material is allowed to reach one end of the apparatus.

Another object of the present invention is to provide a magnetic separator which utilizes drums having magnetized fields located in fixed segments thereof for separating magnetic material from non-magnetic material, which drums do not require the use of scrapers or other devices for removing the magnetic material from their peripheries.

The drawings show a preferred embodiment of the invention and such embodiment will be described, but it will be understood that various changes may be made from the construction disclosed, and that the drawings and description are not to be construed as defining or limiting the scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an elevational view of a magnetic separator which has a plurality of drums constructed in' accordance with the present invention.

FIG. 2 is a vertical sectional view through the plurality of drums showing the' mixture of magnetic and non-magnetic material in the process of being separated.

FIG. 3 is a sectional view of oneof the rotating drums shown in FIG. 2, being taken along the line 3-3 of that figure.

DETAILED DESCRIPTION Turning now to the drawings in greater detail, FIG. 1 shows a hopper having a supply of a heterogeneous mixture of magnetic and non-magnetic material, such as scrap metal chips recovered from various manufacturing operations. The mixture drops through an opening in the hopper 10 onto a tray 12, which tray is adapted to be vibrated in a conventional manner through the mechanism 14, so as to feed the scrap metal chips horizontally toward the right in the direction of the arrow 16. The tray 12 includes an arcuately shaped shovel portion 18 at its downstream end into which the chips will fall when they have reached the right-hand end of the horizontal portion of the tray 12. Means may be provided for spreading the chips on the tray 12 in order to provide a uniform distribution thereof across the width of the shovel 18, and preferably said means comprises a spreader wheel 20 rotatably mounted above the surface of the tray 12 and driven by suitable means (not shown).

A plurality of rotating drums 22, 22 are supported in inclined relationship on an inclined frame 24, and means is provided in the form of a motor 26 for rotating each of the drums 22, 22 in the same rotative directions through a chain and sprocket drive mechanism indicated generally at 28. The rotating drums 22, 22 are constructed of non-magnetic material and each includes a magnetized segment which does not rotate with the drum for feeding magnetic chips successively from the periphery of one drum to the periphery of the next drum. The non-magnetic chips fall downwardly onto an inclined pan 30 where they slide toward the left generally beneath the first drum 22. The said drum is located with at least a portion of its magnetized segment arranged in spaced radial relationship to the arcuate shovel 18 of the tray 12. Some nonmagnetic material thus will drop immediately from the downstream edge, on lip, of the shovel portion 18 into a chute 42 where said material combines with the non-magnetic chip material fed to this point along the surface of the pan 30 and ultimately is deposited onto a take-away conveyor 34. The magnetic material carried from drum to drum in the apparatus shown drops from the last drum 22 in the series onto an inclined ramp surface 36 where it can be carried away on another take-away conveyor (not shown).

Turning now to a more detailed description of the construction of each of the drums 22, 22, FIG. 3 shows a typical drum as comprising a cylindrically shaped stainless steel shell portion 38 having a plurality of longitudinally extending ribs 40, 40 for engaging and agitating the chip material. The shell portion 38 is secured at one end to an end plate 42 of aluminum, which end plate is attached to a rotating shaft 44 through a pin 46. The shaft 44 is journalled as shown in FIG. 1 and continuously driven in the direction indicated through the chain and sprocket mechanism 28 mentioned previously. Still with reference to FIG. 3, the inner end of the continuously driven shaft 44 is rotatably supported on a fixed shaft 48, which fixed shaft extends axially through the drum 22 and is nonrotatably attached at its opposite end to the fixed frame 24 of the apparatus by means of the pin 50. A second aluminum end plate 52 is provided at the opposite end of the shell portion 38 and is rotatably supported on the fixed shaft 48. A permanent magnet 54 is secured to the fixed shaft 48 by a plurality of screws 56, 56 to provide the fixed magnetized field segment in the rotating drum. As best shown in FIG. 2, the fixed magnetized field segment in each of the drums 22, 22 comprises approximately one-half the periphery of the rotating drums 22, 22. The first drum 22, which is located in spaced relation to the shovel portion 18 of the tray 12, has its magnetized field located in the lower half portion of the drum with the result that magnetic material is carried off the shovel portion 18 and in a counterclockwise direction around the drum 22 to the point A. The second drum 22 has its axis of rotation located slightly above and to one side of the axis of rotation of the shaft 44 and the magnetized segment thereof is located below a line connecting said first and second drum axes. Preferably, the polarity of the permanent magnets 54, 54 provided in these drums is so arranged that lines of magnetic force are created between the point A'and a point B on the second drum. This configuration of the magnets 54, 54 in the first and second drums assures that the material transferred therebetween is substantially all of a magnetic nature. The nonmagnetic material will not be attracted to the pole of the magnet 54 in the second drum but instead will drop downwardly onto the inclined surface 30 for delivery to the take-away conveyor 34. The second and all of the subsequent drums 22, 22 on the inclined frame 24 are similarly situated with respect to one another so that magnetic material is caused to move from a point C to a point D on each succeeding drum during operation of the apparatus:

I claim:

1. A magnetic separator for reclaiming magnetic chip material and for culling out very high percentages of nonmagnetic chip materials, and comprising in combination a plurality of non-magnetic drums rotatably supported on parallel axes so that their respective peripheries are adjacent one another, means for driving all of said drums in the same relative direction, means for generating a fixed magnetic field in a non-rotating segment of each of said drums, said drum axes being inclined with respect to one another so that a second drum is arranged slightly above the first and a third drum is located above the second, said magnetic field segments comprising substantially half portions of said second and third drum peripheries and being oriented below a line connecting said second and third drum axes so that the magnetic chip material is attracted to the next adjacent drum material and successively refined, all of said drums having radially outward- 1y extending ribs for engaging said chip material and to break up intermingled formations of magnetic and nonmagnetic chips as they are carried around one drum and transferred to the next drum.

2. A magnetic chip separator as set forth in claim 1 and further characterized by means for feeding a mixture of magnetic and non-magnetic material to be separated into the peripheral path of rotation of said first drum, said means comprising a vibrating tray having an arcuately shaped shovel portion at its downstream end into which the mixture is fed, said shovel portion located in radially spaced relation to said fixed magnetized fieldsegment of said first drum whereby the magnetic material is attracted to said first drum and carried thereon for subsequent transfer to said second drum as aforesaid and a rotary spreader located above said tray for providing a uniform depth of chip material to said shovel portion.

3. A magnetic chip separator as set forth in claim 2 wherein said means for generating a fixed magnetic field in said non-rotating segments of each of said rotating nonmagnetic drums comprises a permanent magnet mounted in an associated portion of each drum.

4. A magnetic separatoras set forth in claim 3 wherein said permanent magnets in said second and third drums are so arranged that their polarity creates lines of magnetic force across and between the adjacent peripheries of said second and third drumsfor assuring that only magnetic material is transferred therebetween.

5. A magnetic separator as set forth in claim 4 and further characterized by an inclined pan beneath said rotating drums for receiving the non-magnetic material not attracted to the magnetized segments of said drums and conveying said non-magnetic material downwardly to a position generally beneath said first drum.

References Cited UNITED STATES PATENTS 465,349 12/1891 Ball.

478,551 7/ 1892 Norton et al.

939,523 11/1909 Ludwick 209230 1,324,529 12/1919 Ullrich 209-230 X 1,543,534 6/ 1925 Ullrich 2O9228 X 1,617,971 2/ 1927 Ullrich 209-231 FOREIGN PATENTS 729,989 3/ 1966 Canada.

. TIM R. MILES, Primary Examiner 

